Utilization of diflubenzuron to control (Gelechia senticetella (Stgr.) (Lepidoptera: Gelechiidae), a dangerous pest of Juniperus excelsa M.B. (Cupressaceae) in Bulgaria

2000

3 Abb., 12 Lit. Ang.

Unselbständiges Werk

3718

200067667

In 1992, experiments were carried out in Bulgaria to control Gelechia senticetella (Stgr.) (Lepidoptera: Gelechiidae), a mining pest on the needles and young shoots of Juniperus excelsa M.B. by commercial products Dimilin ODC-45 and Dimilin WP-25 based on the insect growth regulator diflubenzuron. Two Ultra Low Volume (ULV) treatments were performed - on March 12th and April 16th, during the emerging of the pest larvae out of the infested shoots. Dimilin ODC-45 was applied in a dose of 60-120 ml/ha (27-54 g a.i./ha), dissolved in 5l of diesel oil, and Dimilin-WP-25 - in a dose of 200 g/ha (50g a.i./ha) dissolved in 5l of water. The effect Dimilin ODC-45 was very high - 92.5-97.6 %. The effect of Dimilin WP-25 was unsatisfactory - 63.4-70.0 %, which was most probably due to the fact that the oil emulsions, adhere to the treated plants better than the water solutions, thus ensuring a longer period of action.